Oil well hook



Allg l5, 1950 c. M. RoBERsoN 2,519,288

on. WELL Hoox Filed July 2s. 1947 `2 sheets-sheet 2 INVENTOR. @M ROBERSON BY w1 @m42/aa MW ATTORNEYS Patented Aug. 15, 1950 UNITED STATES ATELNT OFFICE OIL WELL HOOK Claude M. Roberson, Shreveport, La. Application July 23, 1947, Serial No. 762,902

6 Claims. (C1. 294-82) nected together by collars into which the pipe sections are screwed. As the drill is rotated and goes farther into the ground during the drilling operation, more collars and more sections of pipe are added as necessary.

To facilitate the handling of these eXtra sections of pipe and collars, a derrick is constructed over the well sight from which a block and tackle, and hook carried thereby, are suspended. Such an arrangement is called the Well drilling rig. The extra sections of pipe are taken from a stock pile, suspended on the hook over the stand of pipe already in the round, and connected thereto by threading the new sections of pipe to the stand already in the ground. Upon completion of the drilling, or when it is desired to replace the bit of the drill or perform other repair functions on the pipe, the pipe is drawn out of the ground a short distance and its weight supported by suitable means. The section of pipe extending above the ground is then unscrewed from the stand of pipe still in the ground and returned to the stock pile. During such connecting or disconnecting operation the weight of the section of pipe being attached or detached must be supported by the hook in such a manner that the connecting threads will not be injured.

The hook, withn which the present invention is concerned, is carried by the traveling block of the block and tackle and is the connecting link between such block and the pipe sections or whatever other load the rig is handling.

The functions of the hook are several; one being to allow the load to be rotated during the threading or unthreading of the pipe sections, or to prevent the pipe sections, or other load carried thereby, from rotating when so desired. Another function of the hook is to facilitate the speeding up the operation of attaching to and detaching pipe sections from the drilling stand of pipe, as will hereinafter be more fully explained. A further function of the hook is to afford a readily attachable and detachable connecting means between the elevating means and the load carried by the hook. This invention primarily concerns the two first-mentioned functions of the hook.

Hooks for use in connection with oil well drilling must be selectively rotatable with respect to the traveling block so that when a section of pipe is being rotated and threaded to or unthreaded from the stand of pipe in the ground the traveling block will not rotate simultaneously with the hook and cause the ropes of the block and tackle to be twisted. When moving the pipe or other load to another position it is desirable to have the hook stationary or nonrotatable with respect to the traveling block.

The hooks now generally used in connection with oil well drilling present the disadvantage that they must be manually locked or unlocked from rotation. To accomplish such locking or unlocking of the hook it must be lowered near the derrick floor or the surface of the ground, or be raised to the operators position in the derrick so that the locking means may be operated to lock the hook against rotation, or to unlock it and permit rotation with respect to the hook body.

As previously stated the sections of pipe are connected to one another by threads. Hence, if the threads, during connection or disconnection, are not relieved of the weight of the section of pipe being attached or detached they will be damaged. It is one function of the hook to support the weight of the section of pipe being attached or detached during such operation.

Oil well drilling hooks generally used at the present time are so constructed that the hook portion is supported from the hook body by a spring the function of which is to support the weight of the load. The spring in such hooks must be strong enough to carry the weight of the stand of pipe being attached or detached, which weight may range from about 600 to 15,000 pounds, depending upon whether the pipe being handled is light drill pipe or tubing, medium weight or the heaviest drill pipe, with the necessary proportionately heavy collars.

When the pipe sections are being removed from a stand of pipe and the upper pipe section has been disconnected, the spring lifts the hook portion and therefore the disconnected pipe section carried thereby upwardly a short distance from the stand of pipe, thereby freeing the disconnected sections from the stand. The spring has no adjustment for loads of different weight and generally is designed to handle loads of from about 1500 to 2,900 pounds, and very seldom is designed to handle loads as great as the weight of the heavier type drill pipe.

In those instances where the drill pipe or tubing iS of relatively light weight, the spring not being adjustable, frequently will cause too much strain to be applied to the threads of the pipe or tubing with resultant damage to them, to the extent that the pipe or tube must be discarded. When used with drill pipe, which is somewhat heavier than tubing, the spring still may cause too much strain to be applied to the threads causing them to be stripped or otherwise damaged. When the joint is completely separated the spring causes the upper pipe section to jump free. In such a case, the upper section frequently falls back, allowing the pin end of the joint, which has just been unscrewed from the box end of the joint, to strike the machined surface of the box end and cause damage to both of the ends. When it is desired to handle Vdrill pipe or the heaviest type the spring `willnot'support the load, thereby making it necessary for the driller continually to raise the hook and the section of pipe carried thereby to adjust the amount of Iweightxzbeing carried .by the A'threads during the connecting and disconnecting operation, a procedure whichis both awkward and time-consuming.

The present invention contemplates a hoisting hook'assembly which will overcome the aforesaid disadvantage of hooks .currently used, 'particularly the time-consuming, intermittent raisingof the hook during threading or Aunthreading operation to adjust the weight on the threads, and the necessity of manually locking and unlocking the hook `against rotation.

The hook assembly of-the present invention avoids the use of the usual spring for supporting the load by substituting therefor iluid-operated means Icontrollable from a pointremote from the hook. .The hook portion is rotatably supported from apiston which is mounted for reciprocation withina cylindrical hook body. An opening or inlet is formed in the body through which fluid may be supplied under any desired pressure so that the hook will be capable of supporting :any load ranging from the lightest section of tubing to the heaviest stand of drill pipe.

The invention further contemplates a vhook assembly which-includes 'fluid-operated means, operable from the drillers position or other point remote from the hook, for locking and unlockingy the hook against rotation relative to the traveling block.

The invention will lbe-.furtlier described in connection with theaccompanying drawings, but it is to .be understood that such vfurther explanation is merely by way of exemplication V`and that the invention is limited only by the scope of the lclaims appended thereto.

In .the drawings,

Fig. 1 is a perspective view of .an 4oil well'hook embodying the present invention,

Fig. 2 is a vertical sectional view through an oil well hook embodying the present invention, and

Fig. 3 is a horizontal 3-.3 of Fig. 2.

In the form of the invention vshown in the drawings the improved hook assembly comprises a hook 4body I having a substantial @portion of the interior of its walls cylindrical in shape. A hook-.supporting fluid-operated piston 2'is closely fitted within the hook vbody and is reciprocable therein. A'Yhook .3 has -a rectangular shank portion .4 removably secured -thereto and extending upwardly through the lower end of the body. The 4upper end ofthe shank is provided with an enlarged bearing portion `5. The bearing porsectional view .on line tion 5 has a threaded bore extending into its upper side into which is screwed a cylindrical shaft or upper shank portion 6 which extends through the piston and has its upper end formed into an enlarged cylindrical bearing portion 1 rotatably supported in a recess 8 in the piston 2 by ball bearings I0. A pin 9 extends through the enlarged bearing portion 5 and the lower end of the shaft 6 to prevent relative rotation between them. The hook 3, the shank 4, and the shaft 6 comprise a unit which is rotatable with respect to the hook body I.

The bearing portion 1 of the shaft is retained within the recess 8 by a disc I I bolted or otherwise secured to upper or outer surface of the piston-2. Ball bearings I2 are positioned between the inner surface of the disc II and the outer surface of the enlarged cylindrical bearing portion 1 of the shaft 6 to permit relative rotation between the disc and the shaft.

A :normally stationary piston-like partition I3 Vis closely fitted within the hook body and is adapted to t around the shaft 6 below the piston 2. This partition I-3 rests on and is prevented from downward movement by an inwardly-extending abutment or shoulder I4 of the hook body. Suitable resilient sealing means are placed in recesses of the piston 2 and the partition I3 so that a fluid-tight chamber I5 is formed in the hook body between the movable piston 2, and the partition I3.

In order to resiliently support the load suspended from the hook, fluid may be admitted through a conduit I6 which Venters the chamber Ithrough a recess in the "hook body slightly above the upper `surface of the partition I3.

A main bearing member I.1 -is positioned within the lower part'of the hook body around the rectangular shank `of the hook and is rotatably mounted upon an inwardly extendingilange I 8 of the lower'end of the hook body by ball bearings I8. yAtubular-like extension 20 ofthe main bearing I1 .depends from the lower yside lthereof and extends .between 'the shank'4 of the hook and the inwardly-extending flange I8 at the lower end of the hook body. The opening in the main bearing I1 and the extension 20 thereof conforms in size and shape to the rectangular shank 4 of the hook so that the main bearing and hook rotate together; while the outer periphery of the extension 20 is circular and extends through `a similar opening `in Vthe flange I-8 to .permit relative rotation between the hook `body and the main bearing I1 and hook. `The shank 4 of the hook is slidable longitudinally -through'the -ma-in bear-ing member I1, so that when fluid is admitted to the lchamber I5 the hook and the shank thereof will be raised, the shank sliding in the opening of the bearing member.

In order selectively `to prevent rotation betweenthevhook -body and the main bearing and hook, a uid operated lockingmeansis provided comprisinga cylinder y2I positioned in a recess 22 in the hook body. The cylinder is secured in the recess 22 in any suitable manner, such as by a bolt 23 extending through an extension of the cylinder. A latching piston 24fis reciprocally mounted within the cylinderrZI and has'a cylindrical piston rod 25 formed with a squared outer end extending 'through the lower end of the cylinder 2|. The latching piston 24 is normally held in a retracted position within the cylinder 2I by a compression spring 26 positioned `between the' piston 24 and the lower'end wall of the cylinder,

"The upper-outer periphery of the main bearing I 1, as shown in Fig. 3, is formed with recesses 21 any one of which may be brought into registry with a similar recess 28 in thehook body. When fluid under pressure is supplied to the :cylinder 2l through a conduit 29 passing through a recess in the hook body, the piston 24 is Iforced downwardly against the action of the spring 25 and the squared lower end of the piston rod 25 is projected into the space formed by the recess l28 and one of the recesses 21 of the main bearing l1 in alignment therewith thus preventing relative rotation between the hook body and the shank of the hook.

To allow for sudden loading of the hook during operation which sometimes causes pressure within the chamber l5 to be multiplied many times, a spring-loaded pop or relief valve 30 of' conventional design is positioned within the piston 2.

In order to protect the internal working parts of the hook yfrom dirt and resultant damage thereby, a substantially hemispherical cover 3| is bolted or otherwise secured to the upper edge of the wall of body and forms a cover for the open end of the hook body.

A bail extends from the upper part of the cylindrical body l and is the part by which the hook is suspended from thek traveling block of the block and tackle or other supporting means.

From the foregoing it will be seen that fluid under pressure may be supplied to the chamber I5 to prevent downward movement of the piston 2 and thereby resiliently sup-port the load carried by the hook. The pressure of the uid supplied may be vvaried over a wide range to allow adjustment of the hook for use with, for instance, the lightest or the heaviest drill pipe. This is especially advantageous in connecting or disconnecting sections of pipe from the stand of pipe already in the ground.

Should it be desired to disconnect a section of pipe from the stand in the ground the hook is connected to the upper pipe section of the stand and the later is hoisted out of the well until the section of pipe to be disconnected is above the ground. Suitable supporting means then is secured to the pipe to prevent it from falling back into the lwell. Fluid under pressure then is admitted to the ,chamber i5 suiiicient in amount just to support the weight of the section of pipe being disconnected from the threads of the connecting joint. If the piston rod 25 is not already in its retracted -position to permit relative rotation between the main bearing I'! and the hook body pressuire is released from the latching piston 24. The spring then moves the piston 24 and the piston rod 25 carried thereby to their retracted positions withdrawing the squared end of the rod 25 .from its locking position between the main bearing I1 and the hook body, thereby permitting rotation of the hook relative to the hook body and the traveling block. With the hook rotatable relative to the hook body, the section of pipe to be disconnected may be unscrewed in any suitable manner until the threads thereof are disengaged from the remainder of the stand. When the disconnection is com-plete more fluid may be applied to the chamber l5 to cause a gradual lifting or separation of the disconnected section from the remainder of the stand, without any sudden jerking away of the disconnected section and its dropping back 'with possible resultant damage to the connecting threads such as fre- 6 quently occurs when using the ordinary springloaded hook.

The distance of allowable triavel of the piston 2 toward the partition i3 is greater than the allowable travel of the enlarged bearing portionv 5 toward the main bearing Il. As -a result, when no pressure is applied to resist the downward motion of the piston 2, the shank 4 of the hook` will slide longitudinally through the main bearing member Il and the enlarged bearing portion 5*:will descend and rest upon the imain'bearing l1,

vwhich then supports the full load carried by they hook. The hook then may be used merely as a carrier, as for instance when a section of pipe, recently disconnected from the stand of pipe in the ground, is to be carried from the well sight to the pipe stock pile.

When the hook is used merely as a carrier, it generally is desirable to supply iiuid to cylinder 2| so as to project the squared end of the pistonr cover 3i is removed all the internal working parts may be removed from the upper portion of thev cylindrical body.

Various changes may -be made in the details.

of construction without departing from the invention or sacrificing any of the advantages thereof. v

I claim:

l. A hoisting hook assembly comprising a body having its walls in the form of a cylinder, a fluidoperated piston reciprocable within said cylinder and provided with a recess, a partition eX- tending across said cylinder, said cylinder having an inwardly-extending shoulder against which said partition rests, a hook having its shank extending through said partition and through at least a. part of said piston, said shank having an enlarged portion rotatably mounted in said piston recess, said piston, said partition, and said cylinder forming a fluid-tight chamber, and means for admitting uid under pressure into said chamber for resiliently supporting said hook from said hook body.

2. A hoisting hook assembly comprising a body the walls of which form a cylinder, a iiuid-operated piston reciprocable therein and forming a movable end for a duid-tight chamber within said cylinder, means extending across the cylinder to form the other end of said chamber, means for admitting fluid under pressure to said chamber, a bearing member rotatably supported in said cylinder, a hook shank non-rotatable with respect to said bearing member extending through said bearing member and being supported from and rotatable with respect to Said piston, and remotely-operable means for selectively preventing and permitting relative rotation between said bearing member and therefore said shank, and Said body.

3. A hoisting hook assembly comprising a body the walls of which form a cylinder, a Huid-operated piston reciprocable within said body forming one end of a huid-tight chamber within said cylinder, a member extending across said cylinder forming the other end of said chamber, an opening in said chamber for admitting fluid under pressure, a; reliefvalt/eA forminggan'outlet, trono said chamber, a hook having its shank'extending, throughv said part` andA saidx chamber and' rotatably simpuoitted' by said-l piston a bearing rotatably supported: in saidv cylinderv and; surrounding saidshank in nonsrotativefrelation. thereto, and. remotely-010erated4 huid-operated meansfor selectively` permitting; and? preventing relative rotation; between` saidzbearing; and therefore; shank, andfsalid body.y

41 A. hoistinghooli'` assemllvNv comprisinga body the walls: of' which form a. cylinder,- a' fluid-op erated piston reciprocable within said cylinder, a pamtiixion' extending: across said' cylinder, said piston',said partition, and said cylinder forming a. Hind-tightA chamber, means; for admitting uid under pressure to said chamber;. a bearing member.` rotatably mounted within: said cylinder, said bearing member'havingv spacedr recesses;. ak hookI shank nonrotatable with respect to: said bearing memberr extending through said" bearing member4V said` partitionAv and: b'eing rotatably suported from said piston; acylinder attached to said' body, a. fluid-operated piston reciprocabl'e Within said last-mentioned cylinder, a.V rod! exV tending. rom said,` lastsmentioned piston, said last-mentioned piston' and said rodbeing so positioned with respect to saldi main. bearing that said;` rod' may be projected' into the recess therein,` and? means for admittingi fluid to said lastmentionedzcylinder under pressure to project said rod into one of the recesses in saidibearingfmember. to preventrelative rotation thereof with respecttosaid body.

5^; Ashoisting` hookassembly comprising a body the walls of which form a cylinder, a piston Withinsaid cylinder, abearingr member rotatably mountedv in said-cylinder, a hook sha-nk extend-v ing th-roughsaid bearing member and rotatably supported from said piston, a part carried by sald-r shank adapted to rest-uponsaidbearing member, and to support: the hook shank therefrom, and remotely-operable means for selectively prevent ing relative rotation. of` said bearing member and` therefore said hooliA shank, with. respect to said body.

6. Ahoisting hook assemblyy comprising a body, the Walls of which form a cylinder, a duid-op erated piston reciprocable thereinand-forming a movable end of aA u-id-tight chamber within saidcylinder, means extending across the-cylinder to form` the other end of. saidchamber, ahook having the.' shank thereof extending through the means forminglthe other end of said chamber and. having. its` distal end rotatably mounted on said piston and means for admitting iiuid'undery pressure, torsaid chamber.

CLAUDE M. ROBERSON.

REFERENCES CITED The following references' are of record in the i le of this patent:

UNITED STATES PATENTS 

